This absolute encoder (1) is provided with a scale (2) that is movable and has an optical pattern (10) provided thereon, a light-emitting body that emits light that is made to advance toward the optical pattern, a sensor (4) for detecting light from the optical pattern and outputting a signal expressing the intensity of the detected light, and a calculation unit (13) for determining the position of the scale on the basis of the signal from the sensor. In the optical pattern, data encoded from specific data assigned to each of the possible scale positions is replaced with an arrangement of first areas (11) and second areas (12) that can be detected by the sensor with a different light intensity than the first areas. The width of the light-emitting body is narrower than both the width of a portion where the first areas are arranged consecutively and the width of a portion where the second areas are arranged consecutively.